1. Field of Invention
The present invention relates to a chamber for a blood treatment system having a blood inlet and a blood outlet, and a filter element for air separation which is arranged at the head side with respect to the position of the chamber in the operating state and which can be decoupled from the blood present in the chamber in the operating state by means of a further liquid, to a blood hose system and to a blood treatment system.
2. Description of the Prior Art
In known hemodialysis systems a venous drip chamber which is a component of the extracorporeal blood circuit is located downstream of a dialysis filter. Said venous drip chamber provides a bubble-free reinfusion of the dialyzed patient blood at this point. The venous drip chamber is usually not completely filled. There is thus a disadvantageous blood-to-air contact here. To avoid an infusion of blood clots, the venous drip chamber is equipped with a clot trap which is as a rule designed as a screen.
A plurality of examples for drip chambers are already known from the prior art.
DE 32 02 582 A1, for instance, shows a drip chamber in which the blood dripping in does not drop directly into the blood level, but rather onto an oblique inner wall to minimize foam formation and thus the risk of a possible hemolysis.
U.S. Pat. No. 5,330,425 describes a plurality of blow-molded drip chambers for dialysis treatment having a specially located injection site.
U.S. Pat. No. 3,834,386 describes a drip chamber having a septum integrated into the cap of the drip chamber.
The blood inlet into the chamber frequently takes place in the state of the art via a corresponding port whose end is above the blood level. A dripping of the blood into the chamber therefore takes place, which brings along the danger of the formation of microbubbles, with such microbubbles not being able to be separated and being able to be led back to the patient without impediment. These microbubbles can moreover cause hemolysis.
A standard drip chamber usually furthermore has an injection port having a hydrophobic septum and has a venting line which is provided with a hydrophobic membrane, in particular a so-called transducer protector (TDP). The venting line can, on the one hand, be guided via a 3-way valve in the interior of the machine to a pressure transducer for the monitoring of the pressure in the venous drip chamber or can, on the other hand, vent the drip chamber via a pressure reducer, such as is the case on the initial filling of the hose system or of the extracorporeal blood circuit.
A venous drip chamber is furthermore known from WO 2007/050211 A2 in which the blood inlet port and the blood outlet port are arranged in the base of the chamber and wherein a dividing wall is located between the blood inlet port and the blood outlet port. A hydrophobic membrane is let into the cap of the chamber to vent the chamber. The chamber is completely filled with saline solution at the start, with the filling taking place via a blood inlet port. When blood is flowing into the chamber in dialysis operation, the displaced saline solution is supplied to the patient. A certain quantity of saline solution remains in the chamber to decouple the hydrophobic membrane from the blood level. The handling of such a drip chamber is often associated with not insignificant effort and considerable care since it has to be ensured that sufficient saline solution remains in the chamber to decouple the hydrophobic membrane from the blood level and to ensure a correct operation of the drip chamber.